Question

questão 26,ajudas?????

Answer 1

${3}^{x - 1} = 81 \\ {3}^{x - 1} = {3}^{4} \\ x - 1 = 4 \\ x = 5 \\ { (\frac{3}{4}) }^{x} = \frac{16}{9} \\ { (\frac{3}{4} )}^{x} = (\frac{4}{3} {)}^{2} \\ ( \frac{3}{4} {)}^{x} = (\frac{3}{4} {)}^{ - 2} \\ x = - 2$ (a)